Valve.



R. WILSON.

` VALVE.

APPLICATION FILED JAN.21. 1913. 1,111,244. t Patented Sept. 22, 1914.

le 75 2 2. Y s 4 8 SLT e k l0 v/jLZ/Laf'zf J/L/wy/@Z/MU" UNITED STATES PATENT OFFICE.

ROBERT UTIIBON,v F DEEP GOLD MINE, J OHANNESBURG, TRANSVAAL, SOUTH AFRICA.

VALVE.

Bpecidoation of Letters Patent.

Patented Sept. 22, 1914.

' ments in Valves, of which the following is 'a specification.

Thisinvention has reference to valves, the object being to provide a valve constructed for high working pressures and for dealing with abrasive or corrosiveiluids.

A special object'of the invention 1s to provide an improved blow-down valve for the' pump columns in deep mines where not only is the pressure very high, but the water to be dealt with is generally very acld and often also gritty.

The ordinary metal to metal valves and seats when eX osed to, excessively high pressures are liabl) of the flowing fluid, causing escape of the fluid. This is particularly the case when the valve is employed for regulating the flow of a liquid of an acid or gritty nature.

A valve constructed according to this invention is shown in section in the accompanying drawing.

The valve comprises a casing 1 havin a cylindrical internal bore which is pre erably provided by a liner 2. The valve proper consists of a piston 3 packed at lts ends by means of cup leathers or like hydraulic packings 4, which are separated usually by a non-corrosive distance piece 5.

One annular section 6 of the liner is perforated by a number of relatively small ports 74 which rovide communication between the cylin rical bore of the valve and an annular passa e 8 which in turn communicates with t e passage 9; the latter being, in this case, the outlet. The collective area of the ports 7 is preferably made equal to that of the outlet passage. The other passage 10 opens to one end of the casing; it is generally made the inlet and of smaller diameter than the outlet 9.

When the valve is closed, as shown, the piston 3 covers .the aforesaid annular series of ports 7 ;'the distance piece 5 lying immediately over the lports 7 and the packings seating upon the unbroken surfaces 11, 12 of the liner at either side thereof while opening of the valve is effected by traversing the piston along the bore to uncover said ports 7. Consequently, so long as the valve the yielding nature of the pac pressure of the fluid forcing it to conform e to become cut by the action is closed, the piston packings 4 completely exclude the fluid from the piston and from the unbroken liner surfaces 11, 12, which surfaces constitute the valve seat. Moreover, when the valve is lifted, there is little tendency to abrade said surfaces 11, 12, owing to the flow of fluid within the cylindrical bore being substantially longitudinal thereof; while the large How area afforded by the annular series of ports mini mizes the tendency to cutting at that' point. Should either the valve seats or the packings become scored or worn, the valve will nevertheless tend to remain ti ht owing to img and the closely to the metal surface; and the small initial leakages, which in a metal to metal blow-down valve would rapidly develop, are thus avoided.

The individual diameter o the ports 7 is such that the packings 4in passing over them are adequately supported against being torn away and forced through them b the pressure of the li uid. Holes one-eightli of an inch diameter ave been found to be satisfactory with the incoming liquid at 1000 lbs. per square inch pressure.

The piston 'is usually balanced by providmg a passage 13 which puts the spaces 14, 15 at its ends in communlcation. The forces at the valve ends due to the pressure may be so differentiated by adjustment of the area of the valve spindle 16 as to facilitate the movement of the valve against pressure, either when opening or closing it, as may be desired. In the construction illustrated, the passage 13 is formed in the valve spindle 16 which passes completely through the piston. The lower end of the passage 13 is flared; while the inlet passa e 10 is positioned in alinement with sald passage 1 3 and of inwardly converging form. vThe result is that the incoming li uid is cushioned upon itself in the mouth o passage 13 and thereby prevented from seriously damaging the arts of the valve.

at I claim and desire to secure by Letters Patent is:-

1. A valve comprising a casing rovidin a cylindrical valve chamber, the en s of whlch are constantly in communication, a iston working therein and fitted at each en with outwardly directed cup packin an inlet passa e opening to one end 'o cham r, an outlet passage communicating the valve l.

with the interior of the valve chamber by means of a group of relatively small ports in the wall of the chamber, such piston covering said ports to close the valve, and being movable away from the inlet passa e to put the latter in communication with tie ports, and thereby open the valve.

2. A valve comprising a cas` providing a cylindrical valve chamber, t e ends of which are constantly in communication, a piston working therein and fitted at each end with outwardly directed cup packing, an inlet passage opening to one end of the valve chamber, an outlet passage communicating with the interior of the valve chamber by means of a group of ports in the wall of the chamber, said ports being individually so small that the packing cannot be forced a preciably into them, the wall of the chan er about and on either side of said group 'of ports forming a continuous and substantially unbroken surface upon which the packing is constantly seated.

3. A valve comprising a lcasing providingv a. cylindrical valve chamber, a piston struc# ture working therein and provlded at each end with outwardly directed cup packing, an inlet at one end of the casing and directed toward said piston structure, said structure having a longitudinal hole aording communication `between the two ends of the Witnesses:

W. HILLMAN VINCENT.. J. N. VENNING. 

